Collaborative augmented reality

ABSTRACT

Augmented reality presentations are provided at respective electronic devices. A first electronic device receives information relating to modification made to an augmented reality presentation at a second electronic device, and the first electronic device modifies the first augmented reality presentation in response to the information.

BACKGROUND

Augmented reality provides a presentation of a physical, real-worldenvironment that is augmented by additional information, such as audiodata, video data, image data, text data, and so forth. For example, acamera of an electronic device can capture the image or video of aphysical target. An augmented reality presentation of the physicaltarget can then be displayed by the electronic device, where theaugmented reality presentation of the physical target includes the imageor video of the physical target, along with additional data such as anyof those listed above.

BRIEF DESCRIPTION OF THE DRAWINGS

Some embodiments are described with respect to the following figures:

FIG. 1 illustrates an example arrangement that includes multipleelectronic devices associated with displays that can display augmentedreality presentations of a collaborative augmented reality session, inaccordance with some implementations;

FIG. 2 is a flow diagram of a process of an electronic device that isable to display a collaborative augmented reality presentation, inaccordance with some implementations;

FIGS. 3 and 4 are flow diagrams of processes performed by an augmentedreality server to support a collaborative augmented reality session, inaccordance with some implementations;

FIG. 5 is a block diagram of an electronic device according to someimplementations; and

FIG. 6 is a block diagram of an augmented reality server according tosome implementations.

DETAILED DESCRIPTION

Generally, an augmented reality presentation can be created in responseto capture of an image or video of a real-world physical target. Asexamples, the physical target can be a picture in a magazine ornewspaper, a picture on a product box, a geographic landmark, and soforth. A user can point the camera of an electronic device at thephysical target, and in response to the capture (image capture or videocapture) of the physical target, the electronic device can produce anaugmented reality presentation that is based on the physical target.

The augmented reality presentation can include a visual outputcontaining an image or video triggered based on the captured physicaltarget, augmented with additional information (hereinafter referred toas “augmented reality content”). The augmented reality content caninclude audio data, further video data, further image data, text data,and so forth, that is added to the visual output. The visual output ofthe captured physical target can include an image or video of thecaptured physical target (the entirety of the captured physical targetor a portion of the captured physical target), or a representation ofthe captured physical target, or different visual content. In caseswhere the visual output contains an image or video of the capturedphysical target or representation of the captured physical target, thefurther video data, further image data, and/or text data can overlay thevisual output, while the audio data can be output as sound along withthe visual output. An augmented reality presentation can thus be in theform of a multimedia presentation that can include the visual output ofthe captured physical target in addition to augmented reality content.

As an example, the electronic device when pointed at a given picture ina newspaper or magazine may cause an online electronic game to startplaying. The given picture in the newspaper or magazine can be a gamecharacter, an advertisement, or other information associated with theonline electronic game. The capture of such game character or other gameinformation by the camera of the electronic device provides a trigger tothe electronic device to start the online electronic game. As anotherexample, the captured physical target can be a geographic landmark.Based on the capture of the geographic landmark, an augmented realitypresentation can be triggered that can provide a virtual tour of thegeographic landmark, augmented with image or video data, audio data,and/or text data that explain the historical significance of variousaspects of the geographic landmark.

As a further example, the electronic device can capture a chess board,which can cause a chess game to come to life in an augmented realitypresentation such that a user can start playing chess. As yet anotherexample, the electronic device can capture a canvas, which can triggeran augmented reality presentation to allow paint brushes to be virtuallymade on the canvas. In other examples, other types of augmented realitypresentations can be triggered by the capture of other types of physicaltargets.

Traditionally, efficient mechanisms to allow for collaboration amongmultiple users in the augmented reality context have not been provided.In some cases, multiple users may have to share the same electronicdevice to look at a particular augmented reality presentation.

In accordance with some implementations, collaborative augmented realitytechniques or mechanisms are provided to allow for users at multipledifferent electronic devices to collaborate with each other with respectto augmented reality presentations presented at each of the electronicdevices. FIG. 1 depicts an example arrangement that includes electronicdevices 102 and 104. Although just two electronic devices are depictedin FIG. 1, it is noted that in alternative implementations, more thantwo electronic devices can be employed. The electronic devices 102 and104 can be located in the same room, or alternatively, the electronicdevices 102 and 104 can be remotely located from each other, such as indifferent locations of a city, different cities of a country, ordifferent locations across the world.

In some examples, the electronic devices 102 and 104 can include any ofthe following: computers (e.g. tablet computers, notebook computers,desktop computers, etc.), personal digital assistants, smartphones, andso forth. The electronics devices 102 and 104 can have respectivedisplays 106 and 108. In other examples, the displays associated withrespective electronic devices can be separate from the electronicdevices. For example, an electronic device can be a game appliance, aset top box, or other device that is connected to an external display.

As further depicted in FIG. 1, the electronic devices 102 and 104 alsoinclude respective cameras 110 and 112. The cameras 110 and 112 can beused to capture the image or video of a physical target to provide avisual output of the physical target. Both electronic devices 102 and104 can capture an identical physical target 114. Alternatively, inimplementations where the electronic devices 102 and 104 are locatedremotely from each other, the electronic device 102 can capture thephysical target 114, while the remotely located electronic device 104can capture a replica 114-1 of the physical target 114. For example, ifthe physical target is a picture on a newspaper or magazine, then thereplica 114-1 can be the same picture on another copy of the samenewspaper or magazine.

In some examples, assuming that an augmented reality application isrunning in each of the electronic devices 102 and 104, the capture ofcertain physical targets by the respective camera 110 or 112 can triggerthe electronic device 102 or 104 to present an augmented realitypresentation 116 or 118 based on the captured physical target.

The electronic devices 102 and 104 can store information relating tocandidate trigger items that can trigger augmented realitypresentations. Upon capturing an image or video of a physical target,the electronic device can compare the image or video to the candidatetrigger items to determine whether or not an augmented realitypresentation should be triggered.

The information relating to candidate trigger items can be obtained froman augmented reality server 120, which is able to access a trigger itemdatabase 125 that stores information regarding a collection of candidatetrigger items. The electronic devices 102 and 104 are coupled to theaugmented reality server 120 over a network 121. The network 121 can bea local area network (LAN), wide area network (WAN), a wireless network,or some combination of the foregoing.

At least a portion of the information in the trigger item database 125can be communicated to each electronic device 102 or 104 and storedlocally at the electronic device 102 or 104. The electronic device 102or 104 can thus compare characteristics of the captured image or videoof the physical target to the locally stored candidate trigger iteminformation to determine whether or not a match is detected, such that acorresponding augmented reality presentation is triggered.

In alternative examples, the comparison of the captured image or videoof the physical target to the candidate trigger item information can beperformed at the augmented reality server 120.

In performing the comparison of the captured image or video of thephysical target to candidate the trigger item information (at theelectronic device or augmented reality server), various features fromthe captured image or video can be extracted for matching tocorresponding features of candidate trigger items contained in thecandidate trigger item information. A match to a particular candidatetrigger item causes a corresponding augmented reality presentation to bepresented at the electronic device 102 or 104.

In the triggered augmented reality presentation, a visual output of thephysical target 114 (or replica 114-1) is presented, along withcorresponding augmented reality content. The augmented reality contentcan be retrieved from an augmented reality content database 123. In someexamples, the augmented reality content can be retrieved by theaugmented reality server 120 from the augmented reality content database123 and communicated to the electronic device 102 or 104 for inclusionin the triggered augmented reality presentation 116 or 118. As notedabove, the augmented reality content can include any or some combinationof the following: audio data, video data, image data, text data, etc.

In some examples, the augmented reality content database 123 and thetrigger item database 125 are stored in a storage subsystem of theaugmented reality server 120. Alternatively, either or both of theaugmented reality content database 123 and trigger item database 125 canbe located at a remote system accessible by the augmented reality server120 or the electronic devices 102 and 104 over the network 121.

In accordance with some implementations, upon detecting that theelectronic devices 102 and 104 have captured a video output of the samephysical target (where capturing the same physical target can refer toboth the electronic devices 102 and 104 capturing the identical physicaltarget 114, or capturing the physical target 114 and replica 114-1 ofthe physical target, respectively), a collaborative augmented realitysession can be initiated. In the collaborative augmented realitysession, multiple users of the electronic devices 102 and 104 are ableto interact or collaborate with each other with respect to the augmentedreality presentations 116 and 118.

The collaborative augmented reality session can be indicated by theaugmented reality server 120 in response to the augmented reality server120 detecting that the electronic devices 102 and 104 have captured thesame physical target. Upon such detection, the augmented reality server120 can provide an indication to the electronic devices 102 and 104 thatthe augmented reality presentations 116 and 118 are part of the samecollaborative augmented reality session.

Alternatively, the detection that the augmented reality presentations116 and 118 are based on capture of the same physical target can beperformed by the electronic devices 102 and 104, rather than by theaugmented reality server 120. For example, the electronic devices 102and 104 can communicate with each other to communicate informationregarding capture of physical targets such that one or both of theelectronic devices 102 and 104 can compare the captured physicaltargets. When the electronic devices 102 and 104 are located in closeproximity, the electronic devices 102 and 104 can use near-fieldcommunications (radio communications between devices in closeproximity), Bluetooth communications, infrared communications, and soforth. When the electronic devices 102 and 104 are remotely located fromeach other, the electronic devices 102 and 104 can communicate over thenetwork 121 or over another longer-range communications link.

In the collaborative augmented reality session, the users at theelectronic devices 102 and 104 can make collaborative inputs to therespective augmented reality presentations 116 and 118 that may causemodification of the respective augmented reality presentations. As anexample, if the augmented reality presentations 116 and 118 arepresentations of an online electronic game, then the collaborative inputfrom each user can be a game control input that causes game pieces toperform target actions. During the course of playing of the onlineelectronic game, user interactions with the game at the electronicdevices 102 and 104, including movement of game pieces and activation ofgame play controls, can be communicated between the electronic devices102 and 104 using any of a number of communications techniques, such asnear-field communications, Bluetooth communications, infraredcommunications, communications through the network 121, communicationsthrough the augmented reality server 120, and so forth.

As another example, if the augmented reality presentations 116 and 118are part of a collaborative session relating to a canvas on which apicture is to be painted, the collaborative input from a user caninclude paint brush strokes on the canvas, which are to be reflected inboth augmented reality presentations 116 and 118. There can be variousother examples of collaborative inputs for other types of augmentedreality presentations.

Collaborative inputs can be accomplished by use of user input devices atthe respective electronic devices 102 and 104. As examples, the displays106 and 108 can be touch-screen displays that are sensitive to usertouch. As further examples, the electronic devices 102 and 104 caninclude respective user input devices 122 and 124, such as mousedevices, buttons, touchpads, keyboards, voice or other audio inputdevices, and so forth.

In response to a collaborative input received at a particular electronicdevice that causes modification of the respective augmented realitypresentation, information relating to the modification can be propagatedto the other electronic device(s) in the same collaborative augmentedreality session to cause the corresponding modification of the augmentedreality presentation at the other electronic device(s). As depicted inFIG. 1, if the augmented reality modification is made to the augmentedreality presentation 116 at the electronic device 102 in response to auser input, information regarding the augmented reality modification canbe communicated (at 130) to the other electronic device 104.

The communication of the information regarding the augmented realitymodification can be provided directly between the electronic devices 102and 104, or alternatively, can pass through the augmented reality server120. Similarly, when a modification is made of the augmented realitypresentation 118 at the electronic device 104 based on user input,information regarding the augmented reality modification can becommunicated (at 132) from the electronic device 104 to the electronicdevice 102, to cause the corresponding modification to be made to theaugmented reality presentation 116 at the electronic device 102.

In some examples, the augmented reality presentations 116 and 118 thatare part of the same collaborative augmented reality session can providedifferent perspectives of the physical target 114 or replica 114-1. Theaugmented reality presentations 116 and 118 can be virtualthree-dimensional (3D) presentations of the captured physical target, asaugmented with the respective augmented reality content. Depending uponthe corresponding pose (position and angle) of the electronic device 102or 104 with respect to the captured physical target, the perspectiveprovided by each of the augmented reality presentations 116 and 118 canbe different.

Moreover, it is possible for a user to move around with the electronicdevice 102 or 104 during the collaborative augmented reality session.Such movement of the electronic device 102 or 104 can be tracked. Thecollaborative augmented reality presentation 116 or 118 at therespective electronic device 102 or 104 that is moving around can change(in perspective, for example) based on the detected pose of theelectronic device 102 or 104 relative to the captured target.

FIG. 2 is a flow diagram of a process 200 performed at a firstelectronic device (e.g. 102 or 104) in accordance with someimplementations. The process 200 presents (at 202), at a displayassociated with the first electronic device, a first augmented realitypresentation based on a physical target captured by a camera of thefirst electronic device. It is assumed that the first augmented realitypresentation is part of a collaborative augmented reality session thatinvolves multiple electronic devices (e.g. 102 and 104).

The process 200 further receives (at 204) an indication of collaborativemodification made at a second electronic device that displays a secondaugmented reality presentation (which is part of the collaborativeaugmented reality session) based on the same physical target. Theindication of collaborative modification is provided in response to auser input at the second electronic device that causes modification ofthe second augmented reality presentation.

The process 200 then modifies (at 206) the first augmented realitypresentation in response to the indication of the collaborativemodification.

Although reference is made to a process that involves two electronicdevices, it is noted that a similar process can be extended to acollaborative augmented reality session that involves more than twoelectronic devices.

FIG. 3 is a flow diagram of a server process 300 performed by theaugmented reality server 120, in accordance with some implementations.The server process 300 receives (at 302) information relating tophysical target capture from multiple electronic devices, which hastriggered the generation of respective augmented reality presentationsat the corresponding electronic devices. In some implementations, theinformation relating to the physical target capture from a particularelectronic device can include information identifying a trigger itemmatching the captured physical target.

The server process 300 then determines (at 304) whether the physicaltarget capture from the multiple electronic devices relate to the samephysical target. In some examples, this can be based on comparing theidentified trigger items from the multiple electronic devices, anddetermining whether the identified trigger items are the same.

If the physical target capture from the multiple electronic devicesrelate to the same physical target, then the server process 300 provides(at 306) an indication that the triggered augmented realitypresentations at the electronic devices are part of a commoncollaborative augmented reality session. The indication can becommunicated to the multiple electronic devices. For the indicatedcollaborative augmented reality session, the multiple electronic deviceswould respond to any collaborative input that modifies a respectiveaugmented reality presentation by communicating information pertainingto the modification to the other electronic device(s) that is (are) partof the indicated collaborative augmented reality session.

For the indicated collaborative augmented reality session, the serverprocess 300 obtains (at 308) the same augmented reality content toprovide to each of the multiple electronic devices for augmenting theaugmented reality presentations at the multiple electronic devices. Theobtained augmented reality content is then communicated (at 310) to themultiple electronic devices.

If the server process 300 determines (at 304) that the physical targetcapture from the multiple electronic devices relate to differentphysical targets, then the server process 300 obtains (at 312) differentaugmented reality content to communicate (at 314) to the respectivemultiple electronic devices. In this latter scenario, the augmentedreality presentations at the multiple electronic devices are not part ofthe same collaborative augmented reality session.

FIG. 4 is a flow diagram of another server process 400 that can beperformed by the augmented reality server 120 of FIG. 1. During acollaborative augmented reality session that involves multipleelectronic devices, the server process 400 can receive (at 402)information reporting collaborative modifications made at the respectiveelectronic devices. The server process 400 can store (at 404) suchmodification information as state information relating to thecollaborative augmented reality session.

The server process 400 can also determine (at 406) if an additionalelectronic device has been added to the collaborative augmented realitysession. The addition of the additional electronic device to thecollaborative augmented reality session can be based on the augmentedreality server 120 detecting that a captured physical target by theadditional electronic device is the same as or a replica of the capturedphysical target by the multiple electronic devices that are already partof the collaborative augmented reality session.

In response to such detection, the server process 400 can connect (at408) the additional electronic device to the collaborative augmentedreality session. The server process 400 can then provide (at 410) thestate information (regarding the collaborative augmented realitysession) to the additional electronic device, such that the additionalelectronic device can present the same augmented reality presentation(possibly with a different perspective depending on the pose of theadditional electronic device relative to the captured physical target)that is seen by the electronic devices that are also part of the samecollaborative augmented reality session.

Although the tasks of FIG. 3 or 4 have been described as being part of aserver process performed by the augmented reality server 120, it isnoted that in other implementations, at least some of the tasks of FIG.3 or 4 can be performed by one or multiple ones of the electronicdevices 102 and 104. For example, one or multiple ones of the electronicdevices 102 and 104 may be configured as an augmented reality server toperform portions or all of the functionality of augmented reality server120.

In alternative implementations, different roles can be assigned todifferent users involved in a collaborative augmented reality session.As an example, one user can be assigned the role of an administrator,while the remaining users can be participants. An example of wheredifferent roles can be assigned can be in the context of an online boardgame in which the administrator can make modifications in theadministrator's augmented reality presentation, and the modificationsare communicated to the participant users who can then to respond to themodifications. For example, the user with the administrator role candraw a picture in the online board game, and the users having theparticipant role are to guess a word that corresponds to the picturethat is being drawn.

Other types of roles can be assigned to users in the context of othertypes of collaborative augmented reality sessions.

FIG. 5 is a block diagram of an example electronic device 500, inaccordance with some implementations. The electronic device 500 can bethe electronic device 102 or 104 of FIG. 1. The electronic device 500includes an augmented reality application 502, which is executable onone or multiple processors 504. The electronic device 500 also includesa camera 506, a display 508, a user input device 510, a networkinterface 512, and a storage medium (or storage media) 514. The networkinterface 512 allows the electronic device 500 to communicate over anetwork, such as the network 121 of FIG. 1.

The augmented reality application 502 can perform the tasks of FIG. 2,as well as other tasks. For example, the augmented reality application502 can detect the capture of a physical target by the camera 506. Inresponse to the capture of the physical target, the augmented realityapplication 502 compares features of the captured physical target tocandidate trigger item information, which can be stored in the storagemedium (media) 514 or retrieved from the trigger item database 125 ofFIG. 1. Upon detecting a match of the captured physical target to acorresponding candidate trigger item, the augmented reality application502 initiates an augmented reality presentation for the matchedcandidate trigger item for viewing at the display 508. The augmentedreality application 502 can further communicate with the augmentedreality server 120 of FIG. 1 to obtain augmented reality content toaugment the augmented reality presentation.

In addition, the augmented reality application 502 can also receivemodification information relating to modification of an augmentedreality presentation that is displayed at another electronic device thatis part of the same collaborative augmented reality session. In responseto the modification information, the augmented reality application 502can modify the augmented reality presentation presented by the display508. Moreover, in response to detecting a user input that modifies theaugmented reality presentation at the electronic device 500, theaugmented reality application 502 can send information pertaining to themodification to other electronic device(s) that is (are) part of thesame collaborative augmented reality session.

FIG. 6 depicts example components of an augmented reality server 120.The augmented reality server 120 includes an augmented realityapplication 602 that is executable on one or multiple processors 604.The augmented reality server application 602 can perform tasks depictedin FIG. 3 or 4, for example.

The augmented reality server 120 further includes a network interface606 to allow the augmented reality server 120 to communicate over anetwork. In addition, the augmented reality server 120 includes astorage medium (or storage media) 608, which can store variousinformation, including the augmented reality content database 123 andtrigger item database 125 of FIG. 1.

Machine-readable instructions of the augmented reality application 502or 602 can be loaded for execution on corresponding processor(s) (suchas 504 or 604 in FIG. 5 or 6). A processor can include a microprocessor,microcontroller, processor module or subsystem, programmable integratedcircuit, programmable gate array, or another control or computingdevice.

The storage medium (or storage media) 514 or 608 can be implemented asone or multiple computer-readable or machine-readable storage media. Thestorage media include different forms of memory including semiconductormemory devices such as dynamic or static random access memories (DRAMsor SRAMs), erasable and programmable read-only memories (EPROMs),electrically erasable and programmable read-only memories (EEPROMs) andflash memories; magnetic disks such as fixed, floppy and removabledisks; other magnetic media including tape; optical media such ascompact disks (CDs) or digital video disks (DVDs); or other types ofstorage devices. Note that the instructions discussed above can beprovided on one computer-readable or machine-readable storage medium, oralternatively, can be provided on multiple computer-readable ormachine-readable storage media distributed in a large system havingpossibly plural nodes. Such computer-readable or machine-readablestorage medium or media is (are) considered to be part of an article (orarticle of manufacture). An article or article of manufacture can referto any manufactured single component or multiple components. The storagemedium or media can be located either in the machine running themachine-readable instructions, or located at a remote site from whichmachine-readable instructions can be downloaded over a network forexecution.

In the foregoing description, numerous details are set forth to providean understanding of the subject disclosed herein. However,implementations may be practiced without some or all of these details.Other implementations may include modifications and variations from thedetails discussed above. It is intended that the appended claims coversuch modifications and variations.

What is claimed is:
 1. A method comprising: presenting, at a displayassociated with a first electronic device, a first augmented realitypresentation based on a physical target captured by a camera of thefirst electronic device; receiving, by the first electronic device, anindication of a collaborative modification made to a second augmentedreality presentation displayed at a second electronic device based onthe physical target or a replica of the physical target, wherein thefirst and second electronic devices are in a collaborative augmentedreality session initiated upon detection that the first and secondelectronic devices have captured an image or video of the physicaltarget or the replica of the physical target; and modifying, by thefirst electronic device, the first augmented reality presentation inresponse to the indication of the collaborative modification.
 2. Themethod of claim 1, wherein presenting the first augmented realitypresentation comprises presenting the first augmented realitypresentation that contains additional content in addition to the imageor video of the physical target or the replica of the physical target.3. The method of claim 2, wherein the additional content includes atleast one of audio data, video data, image data, or text data.
 4. Themethod of claim 1, wherein the image of the physical target comprises apicture of an object and the replica of the physical target comprisesthe same picture or a picture of a copy of the same object.
 5. Themethod of claim 1, wherein the first augmented reality presentation hasa different perspective of the physical target than the second augmentedreality presentation due to different relative poses of the first andsecond electronic devices to the physical target or the replica of thephysical target.
 6. The method of claim 5, further comprising: tracking,by the first electronic device, movement of the first electronic devicewith respect to the physical target; and modifying the first augmentedreality presentation to update the perspective of the physical targetprovided in the first augmented reality presentation due to change inposition of the first electronic device with respect to the physicaltarget.
 7. The method of claim 1, further comprising: storing stateinformation relating to a current state of a collaborative augmentedreality session including the first and second augmented realitypresentations; and upon detecting addition of a third electronic deviceto the collaborative augmented reality session, providing the stateinformation to the third electronic device to allow the third electronicdevice to display an augmented reality presentation having a stateconsistent with the current state of the collaborative augmented realitysession.
 8. The method of claim 1, further comprising: receiving, at thefirst electronic device, user input to modify the first augmentedreality presentation; and sending, by the first electronic device,modification information over a network to communicate the modificationto the second electronic device to cause the second electronic device tomodify the second augmented reality presentation based on themodification information.
 9. The method of claim 1, further comprising:receiving, by the first electronic device, information regarding a firstrole of a first user of the first electronic device that is differentfrom a second role assigned to a second user of the second electronicdevice.
 10. A server comprising: at least one processor; non-transitorymachine-readable storage medium; and stored instructions translatable bythe at least one processor to: in response to receiving information fromplural electronic devices relating to capture of a physical target,obtain information for augmenting augmented reality presentations at theplural electronic devices; receive information regarding modification ofat least one of the augmented reality presentations at a correspondingat least one of the plural electronic devices, wherein the plurality ofelectronic devices are in a collaborative augmented reality sessioninitiated upon detection that the plural electronic devices havecaptured an image or video of the physical target or a replica of thephysical target; and store state information including the informationregarding modification, the state information relating to a currentstate of the collaborative augmented reality session including theaugmented reality presentations.
 11. The server of claim 10, wherein thestored instructions are further translatable by the at least oneprocessor to: detect an addition of an additional electronic device tothe collaborative augmented reality session; and provide the stateinformation to the additional electronic device to cause the additionalelectronic device to display an augmented reality presentation in thecollaborative augmented reality session that is consistent with theaugmented reality presentations at the plural electronic devices. 12.The server of claim 11, wherein the detection of the addition of theadditional electronic device to the collaborative augmented realitysession is based on the at least one processor determining that aphysical target captured by the additional electronic device matches thephysical target captured by the plural electronic devices.
 13. Theserver of claim 10, wherein the obtained information is at least oneselected from among audio data, video data, image data, and text data,the obtained information to add to a visual output of the capturedphysical target in each of the augmented reality presentations.
 14. Theserver of claim 10, wherein the at least one processor is to further:determine whether the physical target captured by each of the pluralelectronic devices is the same physical target; and in response to thedetermining, indicating that the augmented reality presentations at theplural electronic devices are part of the collaborative augmentedreality session.
 15. An article comprising at least one non-transitorymachine-readable storage medium storing instructions that upon executionby at least one processor cause a first electronic device to: present,at a display associated with the first electronic device, a firstaugmented reality presentation based on a physical target captured by acamera of the first electronic device; receive an indication of acollaborative modification made to a second augmented realitypresentation displayed at a second electronic device based on thephysical target or a replica of the physical target, wherein the firstand second electronic devices are in a collaborative augmented realitysession initiated upon detection that the first and second electronicdevices have captured an image or video of the physical target or thereplica of the physical target; and modify the first augmented realitypresentation in response to the indication of the collaborativemodification.
 16. The article of claim 15, wherein the first augmentedreality presentation contains additional content in addition to theimage or video of the physical target or the replica of the physicaltarget and wherein the additional content includes at least one of audiodata, video data, image data, or text data.
 17. The article of claim 15,wherein the image of the physical target comprises a picture of anobject and the replica of the physical target comprises the same pictureor a picture of a copy of the same object.
 18. The article of claim 15,wherein the first augmented reality presentation has a differentperspective of the physical target than the second augmented realitypresentation due to different relative poses of the first and secondelectronic devices to the physical target or the replica of the physicaltarget.
 19. The article of claim 15, wherein the instructions whenexecution by the at least one processor further cause the firstelectronic device to: detect an addition of an additional electronicdevice to the collaborative augmented reality session, wherein thedetection of the addition of the additional electronic device to thecollaborative augmented reality session is based on the at least oneprocessor determining that a physical target captured by the additionalelectronic device matches the physical target captured by the firstelectronic device.
 20. The article of claim 15, wherein the instructionswhen execution by the at least one processor further cause the firstelectronic device to: determine whether the physical target captured bythe second electronic device is the same physical target; and inresponse to the determining, indicating that the augmented realitypresentation at the second electronic device is part of thecollaborative augmented reality session.